This page provides specific information regarding the EPUB variant
used in "EPUB 3 Best Practices".
The EPUB variant used by this book largely matches that
described in EPUB 3 Best Practices, but there are some exceptions.
Because this is an EPUB 3.0 document, it has both a NAV file (newly defined in EPUB 3)
and an NCX file (required for backward compatibility with EPUB 2).
Both the Nav file (bk01-toc.html) and the navmap hierarchy in the NCX file (toc.ncx)
cover the Chapter and Section levels.
O'Reilly produces a large number
of high-quality technical reference works for software developers.
Let's examine their EPUB archive for EPUB 3 Best Practices.
The file tree contains about 100 files,
a third of which (e.g., fonts, HTML) reside in the OEBPS directory (tsk).
The document contains both *.png and *.png.jpg images; wazzup?
Most (but not all) of the images reside
in the OEBPS/images directory;
the exceptions appear to be used by all O'Reilly books.
The spine entry lists the enclosed content files, in the "normal" reading order.
The toc attribute's value (ncx) tells us to look for toc.ncx,
a file which contains EPUB 2 navigation hints and other metadata.
The guide entry lists only three references:
The cover page is "cover.html".
The toc page ("Table of Contents") is "bk01-toc.html".
The index page is "index.html".
The OEBPS/content.opf file contains two indications that bk01-toc.html is the Nav file.
I'm not yet sure which of these is definitive, reliable, etc:
the guide entry for type toc
the manifest entry for item htmltoc
Looking inside bk01-toc.html, we can tell that it is actually an XHTML file,
which guarantees some useful syntactic decorum (e.g., closing tags).
The NCX Navigation Center eXtended file (toc.ncx) is included,
as required for backward compatibility with EPUB 2.